Phospholipids are ubiquitous in nature and are essential for the lipid bilayer of cell membranes. Their structural and functional properties are pivotal for the survival of the cell. In this study the phospholipids of healthy and cancerous human renal tissues from the same patients are compared with special reference to the electric charge of the membrane. A simple and highly effective normal-phase method is described for analyzing phospholipids content. This work is focused on changes of phospholipids content (PtdIns, phosphatidylinositol; PtdSer, phosphatidylserine; PtdEtn, phosphatidylethanoloamine; PtdCho, phosphatidylcholine) in cell membranes of renal cancer of pT1 stage, G2 grade, without metastasis. Surface charge density of healthy and cancerous human renal tissues was measured by electrophoresis. The measurements were carried out at various pH of solution. Depending on the surface charge density as a function of pH, acidic (C(TA)) and basic (C(TB)) functional group concentrations and their average association constants with hydrogen (K(AH)) or hydroxyl (K(BOH)) ions were evaluated. The process of cancer transformation was accompanied by an increase in total amount of phospholipids as well as an increase in C(TA) and K(BOH), whereas K(AH) and C(TB) were decreased compared with unchanged tumor cells.